From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F93CC10F00 for ; Mon, 25 Feb 2019 21:55:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E19582083D for ; Mon, 25 Feb 2019 21:55:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551131749; bh=YrrfRNY9xwgwsujbyzpQCFAZ/ZoOq+Ei19RxAy91UB4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fAOAtZoTqDdBAkDT4WivbQgsiUsra6w3LTCWzaS82RxhqPdjqPH6a1kjTNQY976tG T2sj5EQNY+cOSgP6j2bwNyFD6wLvYEkigVOIXT7pQ8+Putfo6Ai8jVnYVTK5gvKGWO 2zqKwgH/2urUjveQXWbnUpsgzpp4hI8CAKW22SWY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729732AbfBYVVl (ORCPT ); Mon, 25 Feb 2019 16:21:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:55498 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730687AbfBYVVj (ORCPT ); Mon, 25 Feb 2019 16:21:39 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D13D621841; Mon, 25 Feb 2019 21:21:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551129699; bh=YrrfRNY9xwgwsujbyzpQCFAZ/ZoOq+Ei19RxAy91UB4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2Qi4UuEuKttKnj188Y/butrvi4mRRbz6NJJP5/rwJ9EeTQqH8K0rHEIr6Mku9iPrw Bj9PLks9raI3GO9eu9rakzUvMhxOD6Q0FB8FxS+RDuFkVG2bQ2IT80+Cql/emQgt74 w/f9sPbidzRKLojQYcUwTpEu0RPzlmEBiVdEIWTU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nitin Rawat , Andrey Ignatov , Alexei Starovoitov , Sasha Levin Subject: [PATCH 4.19 039/152] bpf: Fix [::] -> [::1] rewrite in sys_sendmsg Date: Mon, 25 Feb 2019 22:10:31 +0100 Message-Id: <20190225195046.355327872@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190225195043.645958524@linuxfoundation.org> References: <20190225195043.645958524@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit e8e36984080b55ac5e57bdb09a5b570f2fc8e963 ] sys_sendmsg has supported unspecified destination IPv6 (wildcard) for unconnected UDP sockets since 876c7f41. When [::] is passed by user as destination, sys_sendmsg rewrites it with [::1] to be consistent with BSD (see "BSD'ism" comment in the code). This didn't work when cgroup-bpf was enabled though since the rewrite [::] -> [::1] happened before passing control to cgroup-bpf block where fl6.daddr was updated with passed by user sockaddr_in6.sin6_addr (that might or might not be changed by BPF program). That way if user passed [::] as dst IPv6 it was first rewritten with [::1] by original code from 876c7f41, but then rewritten back with [::] by cgroup-bpf block. It happened even when BPF_CGROUP_UDP6_SENDMSG program was not present (CONFIG_CGROUP_BPF=y was enough). The fix is to apply BSD'ism after cgroup-bpf block so that [::] is replaced with [::1] no matter where it came from: passed by user to sys_sendmsg or set by BPF_CGROUP_UDP6_SENDMSG program. Fixes: 1cedee13d25a ("bpf: Hooks for sys_sendmsg") Reported-by: Nitin Rawat Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- net/ipv6/udp.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 76ba2f34ef6b1..cab8b2b647f96 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1322,10 +1322,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) ipc6.opt = opt; fl6.flowi6_proto = sk->sk_protocol; - if (!ipv6_addr_any(daddr)) - fl6.daddr = *daddr; - else - fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ + fl6.daddr = *daddr; if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) fl6.saddr = np->saddr; fl6.fl6_sport = inet->inet_sport; @@ -1353,6 +1350,9 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) } } + if (ipv6_addr_any(&fl6.daddr)) + fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ + final_p = fl6_update_dst(&fl6, opt, &final); if (final_p) connected = false; -- 2.19.1